A hospital acquired infection (HAI) is a very serious problem in the United States and worldwide. Current estimates are that 99,000 people die annually in the U.S. from these infections. An important and rapidly emerging HAI is Clostridium difficile (C. diff.). In 2008, the Association for Professionals in Infection Control and Epidemiology (APIC) performed the largest and most comprehensive study of Clostridium difficile rates to date which demonstrated the severity of this problem. This study was a survey of 12.5% of acute care hospitals in the United States, and it found that 13 of every 1000 hospitalized patients were infected or colonized with C. diff. (94.4% were infected). This was 6.5 to 20 times higher than previous estimates because those studies were limited in scope. Of those patients infected, 72.5% were considered to be HAI's. In addition to its increasing presence, C. diff. infections are becoming more virulent; the mortality rate has increased from 1.2% in 2000 to 2.2% in 2004. The incidence of deaths from C. diff. was greater than the incidence of infections from all other intestinal infections combined. The cost of treating these infections in the US is staggering and is estimated to be $17.6 million to $51.1 million per day, with some estimates indicating an annual cost in the U.S. of $1 billion to $3.2 billion. There are also additional costs incurred outside of healthcare facilities that were not included in these estimates, such as lost productivity, pain and suffering of the patients and the time that medical professionals spend treating them, making this a multibillion dollar healthcare problem.
C. diff. infections are also becoming more aggressive as evidenced by the increasing mortality rate from this infection which was 1.2% in 2000 and 2.2% in 2004. This is most likely due to the emergence of a new strain of C. diff., termed ribotype 027, which is now the most virulent and common cause of infectious diarrhea in hospitals and long term care facilities in the United States, Europe and Japan. Its increased virulence is due to the production of twenty times more of the two main C. diff. toxins and one additional toxin which produce increased damage of the colonic mucosa and increased episodes of sepsis. This strain of C. diff. is also more resistant to standard therapy and more likely to relapse than any other present strain.
Numerous studies and historical information support the fact that the majority of C. diff. infections and other HAI's result from poor adherence to proper hand hygiene by healthcare personnel. Studies have shown that 60% of physicians and nurses caring for C. diff. infected patients from their hands. Poor hand hygiene and unreliable activity of hand sanitizers against C. diff. have resulted in the rapid growth and widespread occurrence of healthcare associated diarrhea caused by this organism which creates significantly negative health impacts on patients and staff. The rapid growth of C. diff. infections has earned it the recent distinction as “the new superbug on the rise in hospitals.” Poor hand hygiene is a major challenge in controlling the spread of C. diff. infections because no currently available hand sanitizers are active against it or any other spore forming bacteria.
There is an obvious need for an effective hand hygiene strategy that can evaluate the rapidly emerging problem and at the same time promote hand hygiene compliance among healthcare personnel.
There are many anti-microbials on the market which can potentially be used to combat this and other microbes. One such drug is polyvinylpyrrolidone complexed with iodine, which is widely recognized for its anti-microbial properties. This complex is also widely known as povidone-iodine. Since the iodine is tightly complexed, germicidal properties can be obtained without the toxicity or staining concerns associated with compositions containing elemental iodine. Its use in medicine and veterinary medicine as an anti-infective is widely recognized. Products with 5-10% povidone-iodine are over the counter drugs.
Unfortunately povidone-iodine complexes have a short shelf-life, as the iodine chemically decays. U.S. Patent Application No. 2004/0122105 which discloses in Example 33 thereof a povidone-iodine complex containing a tertiary amide, EDTA, PCA, TEA, lauricidin, beeswax, dimethicone, Triton X-100, Nonoxynol-9, Merquat 550, Merguard 1200, propolis, propylene glycol, chlorohexidine gluconate solution, and Carbomer 940 NF, and a final pH of the composition being 4.4, has a shelf life of about 12 months.
Another iodine-povidone product, called Microdine, manufactured by Microorganics LLC, has a pH of 3.6 and a shelf life of 16 months.
But, an antiseptic crème distributed nationwide requires a long shelf-life. A 12-month shelf life is only marginally acceptable. An 18-month shelf life or even better, a 24 month shelf life is preferable.
The present invention is directed to a povidone-iodine formulation that overcomes the aforesaid problems and has a long shelf life.